Field of the Invention
This invention is in the field of tools used to bend and form sheet metal.
Airflow conduits used in conjunction with furnaces and air conditioning systems are in many cases formed at the building construction site. Construction personnel must therefore bend sheet metal shipped to the construction site in a flat state in order to configure the various conduits as required by the particular heating and cooling system. One of the co-inventors hereto devised a prior art sheet bending tool as shown in FIG. 1 to facilitate the bending and shaping of the flat sheet metal into the conduit configuration.
The prior art tool 20 includes a pair of right angle irons or members 21 and 22 having co-planar base walls 23 and 24 integrally joined to a pair of upstanding and parallel walls 25 and 26. A pair of spacers 27 and 28 are positioned between walls 25 and 26, respectively, at the opposite ends 30. Spacers 27 and 28 are secured to the inwardly mutually facing surfaces of walls 25 and 26 by welding or other suitable means. A slot 31 extends through tool 20 between walls 25 and 26, and between the inwardly facing edges of spacers 27 and 28. Likewise, slot 31 extends downwardly between base walls 23 and 24 allowing the flat sheet metal to be extended into the slot with the tool then being rotated about its longitudinal axis 32 to form a bend in the sheet metal.
Heretofore, the worker bending the sheet metal would grasp one end of tool 20 and rotate the tool about axis 32. Due to the relatively large size or width of sheet metal extending through slot 31, the application of force to rotate tool 20 is very tiring to the worker, particularly when a large amount of sheet metal is required to be formed to the various conduit configurations.
We have therefore designed a modified sheet bending tool having a leverage means to assist in the application of rotary force to the tool. Further, we have provided measurement and instruction indicia on the tool to assist in the use of the tool.